The key to solving this problem is density. Density determines the mass of a molecule for a certain volume. Kia is given a beaker containing 100 g which volume is at <span>100 mL mark. Then the density of the liquid would be:
</span>density=mass/volume
density= 100g/ 100ml= 1g/ml
If t<span>he water now comes up to the 50 mL mark, then the weight would be:
</span>density = mass/volume
mass = volume * density
<span>mass = 50ml * (1g/ml)= 50g</span>
Answer: A) 3.21 g
Explanation:
According to the law of conservation of mass, mass can neither be created nor be destroyed. Thus the mass of products has to be equal to the mass of reactants. The number of atoms of each element has to be same on reactant and product side.

We are given:
Mass of iron = 5.58 g
Mass of iron sulphide = 8.79 g
Mass of sulphur = x g
Total mass on reactant side = 5.58 + x
Total mass on product side = 8.79 g
Applying law of conservation of mass, we get:
Hence, the mass of reacting sulfur is 3.21 g.
The shape of a protein molecule resembles BEADS ON A STRING.
Proteins are macro molecules that are formed from amino acids. There are different types of amino acids, thus, different amino acids combine together to form different types of protein. This means that, proteins are formed from sequences of amino acids; they are long chains of different amino acids, that is why, they are likened to beads on string.
The structures of proteins are in three dimensions, they are primary, secondary and tertiary structures. The primary structure refers to the sequence of the amino acids in a protein. The amino acids in the primary structure are linked together by peptide bonds.
I'm having trouble with this one. At the very least, they both purify water. If I'm not mistaken, distillation is part of the process of purifying water.
Really sorry, I hope I helped at least a little! If you have any other questions I might be able to answer better, let me know..
Plasma membrane is the answer